5f0 



AN'IfiSAT ON MOSIC. 



tiiad, C, E, G ; G, B, D : or F, A, C ; nntl 

 the succession of these triads, in various forms, 

 is sufficient for the accompaniment of any 

 simple melody. A regular melody always 

 terminates by aa ascent or descent of one 

 degree to the key note ; the last note but one 

 must therefore be alwa^'s B or D : ami both 

 of tliese being in the triad of G, G is Called 

 the governing note, or the dominant of C ; 

 and F, being in the same manner governed by 

 C, is called its snbdominaut. And it is usual, 

 in all regular compositions of any length, to 

 depart for a short time from the principal 

 harmony of the key note, and to modulate 

 into the key of the dominant, then to re- 

 turn, and to modulate for a still shorter time 

 into the subdominant, before the final close 

 in the tonic or key note. It is necessary there- 

 fore, 'for greater variety, to complete the 

 scale of the dominant, as well as that of 

 every other note which may be occasionally 

 introduced as a principal key note ; but to do 

 this with mathematical accuracy, in'the same 

 proportions as have beeti explained, would 

 be practically impossible, and even theoreti- 

 cally inconvenient : hence arises the neces- 

 sity of tempering some intervals, to make the 

 others more tolerable, without too much in- 

 creasing the number of sounds. It has been 

 found sufficient in practice, to add five 

 notes to the seven which have been enume- 

 rated ; but the best proportions of these have 

 not yet been absolutely determined : some 

 have made all the twelve intervals equal : 

 others have left the whole scale of C perfect : 

 others again have taken a middle path, and 

 have introduced a slight imperfection into 

 this key, in order to make the neighbouring 

 ones the less disagreeable. The least circuit- 

 ous introduction of these notes is shown in 

 the third table, together with the proportion 



that they bear to C when thus considered. 

 They are denominated nearly in the Ger- 

 man manner, the addition of the syllable 

 "is" signifying what the English call sharp, 

 and the French dike, and that of " es," flat, 

 or bcmol. 



But a still greater variety being required 

 than these major scales afford, it has been 

 found, that the interval of a fifth may be 

 agreeably, though somewhat less harmoni- 

 ously, divided, by placing the minor third 

 below, instead of above, the major; so that 

 C may be to E as E was toG, and conse- 

 quently E to G as C was to E. The E, thils 

 depressed to '|, diffeis but by a comma, or 

 in the ratio of 80 : 81, from the Ees found 

 above, as the 4th of Bes ; therefore the same 

 string serves for both notes; and the scale 

 becomes C, D, Ees, F, G, A, B, C ; wliich 

 is the ascending minor scale, the A and B be- 

 ing retained as leading best towards the key 

 note, and the major triad of the dominant be- 

 ing therefore necessary to the cadence. But 

 in descending, the triad of the subdominant 

 Fmay conform to the character of the minor 

 mode, and Aes is substituted for A; and 

 most frequently Bes for B, as dividing the 

 interval from C to Aes more equally and 

 more melodiously. 



Thus we have a pretty comprehensive 

 view of the most usual practical relations of 

 all the notes to each other. Their use as dis- 

 cords is somewhat more complicated, and 

 would lead further into the science of music 

 than is consistent with the nature of so sum- 



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